Slat tilting mechanism for venetian blinds



Nov. 17, 1953 H. NELSON 2,659,431 SLAT TILTING MECHANISM FOR VENETIAN BLINDS Filed Jan. 18, 1950 INVENTOR HMRY 150 BY M 27,4; 4

HIS ATTORNEYS Patented Nov. 17, 1953 SLAT TILTING MECHANISM FOR VENETIAN BLINDS Harry Nelson,

New York, N. Lorentzen Hardware Mf Y., assignor to Corp., New York,

N. Y., a corporation of New York Application January 18, 1950, Serial No. 139,184

8 Claims. (01. 160-477) This invention relates to Venetian blinds and, more particularly, to Venetian blind slat-tilting mechanism.

A Venetian blind is essentially a series of parallel articulated slats which are supported by two or more depending ladder tapes. Slat-tiltin mechanism is provided which includes some type of horizontally pivoted tilt member at the top of the blind from which the ladder tapes are suspended. Since the slats of the blind are thin and more or less flexible, it is usual to provide a heavier slat or bottom bar at the lower ends of the ladder tapes. Lift cords are customarily tilt member when it is desired to raise the blind, the slats accumulating on top of the bottom bar as it is raised.

It is usual to provide a tilter, which is usually of the worm and gear type, for oscillating the tilt member so as to tilt the slats in either direction from level or blind-open position. There is usually some lost motion or play in the tilting mechanism due to normal operating clearance as well as normal wear of the parts. When the slats are in substantially level position, this play may be objectionable in that the wind at times has a tendency to vibrate or oscillate the slats and tilt member through this lost motion in an objectionable manner. When the slats are tilted in either direction from horizontal, they are biased towards the horizontal by the weight of the 'bottom bar since the bottom bar is raised somewhat as well as being tilted by the tilting of the slats. The force of the wind is not suflicient to overcome such bias, and thus the lost motion in the tilting mechanism is not then ob- J'ectionable since the slats and the tilt member are not oscillated through the lost motion.

According to the present invention, frictional resistance i interposed against revolution of the tilt member when the slats are in substantially level position. As the slats are rotated in either direction from level position, the frictional resistance becomes inoperative so as to permit free turning of the slats and tilt member, thus contributing to an easy-operating blind. This is of particular importance in a blind having a socalled escapement tilter as disclosed in my Patent 2,174,994, issued October 3, 1939, in which the gear-sector may be rotated out of mesh with the worm to permit equalizing of the depending ends of the tilt cord. "In such a construction, it

is necessary that the tilt member and gear-sector freely rotate back into engagement with the warm to provide for remeshing of the worm and the bottom bar towards the gear after escapement has occurred. Such a tilter is, to all practical purposes, irreversible, in that torque imposed on the gear by pulling on the ladder tapes will not cause rotation of the worm.

In the form shown, the invention plied to an enclosed metal head bar construction of the type shown in my Patent 2,629,434 and embodying a tilt rod cradle of the type disclosed in my Patent 2,622,673, the tilt member being formed of a tilt rod and tape rockers gensimilar to those shown in the former apto produce frictional engagement of the tape against the cradle when the slats are in substantially level position, this frictional resistance disappearing as the tilt member is moved to rotate the slats in either direction from the horizontal.

An object of the present invention is to provide a Venetian blind head bar assembly in which the slats are held against idle movement, to provide such slats are reis clearly defined in the appended from the pertinent prior art. The best formv in which I have contemplated applying my invention is illustrated in the accompanying drawings forming part of this specification, in which:

Fig. 1 is a front elevation of of the head bar being broken away.

Fig. 2 is a top plan view of the blind shown in Fig. l, the lift cord and tilt cords having been omitted.

Fig. 3 is a vertical section of the tilt rod cradle, rod taken on the line 33 of Fig. 2.

worm and gear shown islt'roci bein oscillatable'by the a range oi about 90in either oi gravity An end flange 21 3 Fig. 4 is a horizontal fragmentary section oi the assembly of Fig. 3 taken on the line 4-4 thereof.

Fig. is an end view of the tape rocker. Referring now to Figs. 1 and 2, the Venetian blind there shown comprises a head bar assembly oi the enclosed-metal-head type, in which a channel-shaped sheet metal head bar I. supports and encloses the operating mechanism oi the blind. The operating mechanism within the head bar H located adjacent one end of the head bar, a cord lock l2 located adjacent the other end of the head bar, and a pair oi tilt rod cradles I4, I4 located between the tilter and cord lock and forming bearings for supporting a tilt rod extending lengthwise oi the head bar and engaged with the tilter.

tilt rod l5, one above each tilt rod cradle, II, the

tilt rod and tape rockers comprising a tilt mem her. The tilt rod I5 is preferably noncircular ingress section so as to nonrotatably engage a gear-sector contained within the tilter H' and the tape" rockers 16,16;

the blind, two oi'which are shown in Fig. 1, are supported in parallel relation below the head bar III by a pair oi ladder tapes [8, I8. The upper ends oi the branches at the ladder tapes are led through slots is formed in the bottom wall oi the head bar II and have terminal loops engaging one on each side rockers it, it so as to suspend the ladder tapes and slats'irom the tilt member. mt cords to, 28, reeved through the cord lock it and the tilt rod cradles i4, ll, pass down through holes (not shown) in the slats ii at the blind, the ends of the hit cords being attached to the bottom bar.

A tilt cord 2| is reeved about a cord pulley 22 of the tilter, the two ends oi the cord being led downward through a slot 2 in the bottom wall oi the head bar. The tilter llisoperated by pullingoneor theother oitheendsoithetiit cord to as'to'rotate the cord pulley it, and rotI-te'the tilt sector mechanism.

The tilt rod l5 and tape rockers it, i! are in Figs. 1 and 2 in slat-levelposition, the tilter H through direction to opl8, It in unison soras'to tilt the slats IT to blind closed position in either direction. In tiltmg the'slats to blind-closed in either-direction, the centcroi gravity or the bottom bar is raised somewhat, theiorce serving to bias" the tilt rod l5 and cradles i4, 14 towards slat-level position. This usualcharacteristic oi Venetian blinds B made the tilter ii is preia'ably oi the eecapement type shown in my Patent No. 2,174,994 The biasoithetiltrodserves to remesh the gear sector with the worm aiter t has occurred. The general head bar organimtion is shown and described in'greater detail in my Patent 2,529,434.

The tape rocker II, It each have a cylindrical or" drum-hire body '20 which is" provided with lingers for engagin thelooped ends oi the it, 13, branches resting against thesuriace oi the body. is located at each end oi the tw rocker body it, this flangeproiecting'inwardly andhaving an arcuate portion concentric with the axis of the body and provided with a noncircular opening corresponding in" rod "by means 01! ac gm shape towards siat icvel a single vertical be accomplished by his the::zone 3B 01 the arcuate end flange, which is under the tab 35 when the with the cross-section oi the tilt rod l5. Preierably, the tape rocker end flanges 21, 21 are each provided with a circular outwardly pressed bead 30 concentric with the arcuate portion oi the flange and spaced inwardly somewhat irom the edge thereof, this bead serving as a bearing tor the tape rocker against a vertical flange 25 of the associated tilt rod cradle ll.

The tilt rod the type shown in my Patent 2,622,673 in which flange 25 at one end of the tape rocker 16 supports the tilt rod l5. Each tilt rod base portion II which is adapted to be secured to the bottom wall oi the head bar In at eac 'ladder tape it. The cradle base ii is provided with aeord guide pulley (not shown) facilitating leading the lift cord upwardly through the blind slats and longitudinally oi the head bar.

The vertical flange 2B or each tilt rod cradle l4 projects upwardly from one end oi the cradle base andihas' an upwardly openin semicircular bearing 84 for receiving and supporting the tilt rod I5. An inner side (towards the base) of the flange 2t adiacenttbe bearing :4 is flat and extends perpendicularly to the tilt rod in order to provide a smooth surface to be contacted by thecireuiarbeadiloithetspe rocker lisoas to limit endwise movunent oi the tape rocker in that direction. A driver or tab Ii, which may be formed from the flange ll, overlies the end tape rocker to limit endwhe tape rocker in the other direction so as to keep the tape rocker centered over the cradle and the opminss in the head bar provided for at the ladder tapes. Preterably, the tab 85 is located diametrically opposite the connection of the end flange 21 with the rest rocker body when the slats are in Fig. 3) to permit in both direc- This organization is described more lull: in my Patent 2,622,673.

according-to the present a irictional resistance against rotation when the tilt member is in siat level position. This may inwardly inclining or deiormportion oi the oi the vertical'nsnge, 2i. The degree 0! inclination or deiormation is chosen so as to offer himcient resistance to rotation oi the tape rocker to prevent vibrational oscillation oi the blind slats and the tilt member by the wind, but to permit easy manual tilting oi the slats in the usual manner by means of the tilt cord 2| and tilter ll. Preferably. each end flange 21 0! each tape rocker it is similarly iormed to iacilitate assembly, in that the tape rocker It may then be assembled without regard to which end is'associated with the vertical flange 25 o! the cradle 14.

While'the irictional resistance against tilting oi the blind could be made operative regardless how far the slats were tilted, such as arrang ment has certain disadvantages in that, as the slats are tilted in either direction irom the horihorder to tilt due to the iact the center of and and the iorce of to bias the blind inter-posing frictional resistance only when the slats are in substantially level position tends to equalize the force required to tilt the blind, regardless of slat position. Further, when Venetian blinds are equipped with escapement tilters of the type in which the gear segment is permitted to run out of mesh with the worm to compensate for slippage of the tilt cord on the cord pulley, it is essential that the tilt member be free to rotate when the slats are tilted to a maximum in either direction to insure remeshing of the worm and gear. Since, when the slats are tilted from horizontal position in either direction, the slats and tilt member are biased towards such level position, this bias will serve effectively to prevent vibration of the slats and tilt member due to action of the wind.

I claim:

1. In a Venetian blind of the enclosed-head type having a channeLshaped head bar provided with fittings for supporting a longitudinally extending tilt rod, including a tilter of the worm and gear type in which the gear may be run out of mesh with the worm and two or more tilt rod cradles, and in which a tape rocker is mounted on a tilt rod adjacent each cradle, the improvement which comprises: at least one of the tape rockers having a generally circular end flange concentric with the axis of rotation of the tilt rod and the adjacent cradle having an upstanding flange provided with portions extending closely adjacent both sides of the end flange of the tape rocker, a portion of the end flange of the tape rocker being of such axial extent as to frictionally bind between the adjacent portions of the cradle when the slats are in substantially level position, the remainder of the end flange of the tape rocker beyond the zone of said firstmentioned portion being of lesser axial extent than the flange-receiving space between the portions of the cradle, so that the binding portions of tape rocker and tilter is moved out of engagement upon rotation of the tape rocker to move the slats towards blind-closed position.

2. In a Venetian blind, a slat tilting mechanism including a horizontally pivoted tilt member, a plurality of slats suspended in parallel relation from said tilt member, and a pair of elements, one of said elements being stationary and the other of said elements being rotatable with the tilt member, the rotatable element rotating on a fixed axis and having a surface which frictionally engages the stationary element when the slats are in substantially level position to interpose a frictional resistance to rotation of the tilt member, said surface of the rotatable element being free from contact with the stationary element at zones a relatively short distance on either side of the mid-point of such surface, so that such elements cease to interpose a frictional resistance to rotation of the tilt member as the slats are moved from slat-level towards blindclosed position.

In a Venetian blind, a head bar, a plurality of tilt rod cradles mounted thereon, a longitudinally extending tilt rod journalled in said cradles, a plurality of tape rockers mounted on the tilt rod, a plurality of slats suspended in parallel relation from said tape rockers, an irreversible tilter of the worm-and-gear type connected with the tilt rod, and means for frictionally resisting rotation of the tilt rod when the tilt rod is in slatlevel position and for allowing the tilt rod to be freely rotated by the tilter throughout a substantial range on either side of slat-level position including each terminal tilted position of the tilt rod, said last-named means comprising a first element formed on an end flange of one of the tape rockers, a second element formed on the tilt rod cradle adjacent to and cooperating with the first element, the first element having an extended frictional surface forming a cam and the second element being frictionally engageable with said cam, the elements being so located with respect to the tilt member, the head bar, and each other that, at slat-level position of the tilt member, the second element engages the cam at substantially the mid-point of the latter, the cam tively short distance on either side of such midpoint of the cam, the second element remaining disengaged from the cam throughout the range of slat-tilting beyond such zone of disengagement on either side of slat-level position.

4. In a Venetian blind of the enclosed'head type having a channel-shaped head bar provided with a, tilter of the worm-and-gear type in which the gear may be run out of mesh with the worm, two or more tilt rod cradles, a tilt rod rotatably and a tape rocker end flange of the tape rocker beyond the ends 01 the flrst portion being of lesser axial dimension than the distance between the opposed portions of the cradle, the binding portions of the tape rocker and cradle being moved out of engagement upon rotation of the tape rocker to move the slats towards blind-closed position.

5. In a Venetian blind: a head bar, a longitudinally extending tilt member having a generally radially extending flange, a plurality of slats suspended in parallel relation from said tilt member, a tilter connected with the tilt member, and an element fixed on the head bar adjacent to and cooperating with the radially extending flange of the tilt member, the radially extending flange having a portion of greater axial extent binding against the fixed element at slat-level position of the tilt member to set up added frictional resistance against oscillation of the tilt member, the portion of said flange of greater axial extent moving out of engagement with said element as the slats of the blind are tilted slightly in either direction from slat-level position.

6. In a Venetian blind: a head bar, a longitudinally extending tilt member having a generally radially extending flange, a, plurality of slats suspended in parallel relation from said tilt member, a tilter connected with the tilt member, and

slot formation receiving the radially extending member, said radially extenda portion of greater axial extent binding within said slot formation at slatlevel position of the tilt member to set up added frictional resistance against oscillation of the tilt member, the portion of said flange of greater may be run out 01 'mesh with the warm at bll q- References Cited ln the file 01 this, patent.

s'ra ras PATENTS Number Name Nelson Lorentzen Sherwood Date 06. 3, 1939 Nov. 18.1911

Nov. '1, 1950 

